replacing bad caps on a Series 3

OK, I have a lifetime Series 3 (OLED/250GB) that is now in the dreaded reboot loop. I had this happen on another lifetime Series 3 (500GB), but it turned out to be the hard drive. Once it was replaced (& reimaged), it worked fine & is still going. Not on this one though.

I removed its hard drive & ran the WD extended test. Everything came back clean. I even slipped this hard drive into the (previously mentioned) working series 3 & it worked fine so I know its not the hard drive & that is good.

Now, I did notice a cap was bulging so I took it to a local shop that wound up charging me about $18 to fix it. However, after re-installing the power supply, its still rebooting. Even tried the working Series 3's (500GB) hard drive in it and no luck as it still reboots. So apparently that is not the only cap that is bad. I probably should have stressed checking ALL the caps the first time around, but I don't think I did and simply pointed out the bulging one. Live & learn.

I might take it back to my repair shop and see if they can replace the needed caps? Are there specific ones that go bad? If so, which ones? Is there maybe some online tutorial or picture of the ones that tend to be bad so I knwo the location of them (since there are numerous ones on it). Or are they all pretty much going to go bad at some point?

I thought about trying to do it myself as I have heard its not hard at all. Have never really worked too much with soldering so this is why I have just had a local place do it. They give free estimates so it might just be easier to see if they can do it, but wondering if I should point out certain ones to them that might be bad.

What ACTUALLY happens is a property called "equivalent series resistance", or ESR, changes. For a lot of stuff like power supplies, you need low ESR caps. But as they age, the ESR value rises, sometimes quite significantly.

Now, a cap's that burst, bulging or leaking is an obvious one in which its ESR has risen to the point it doesn't work anymore (as they age and ESR rises, they heat up even more, so they age even faster). However, they don't always do that - the ESR can rise as the electrolyte degrades (cheap caps) but not to the point where they show visible changes.

The general rule is to replace all electrolytic caps in the power supply with good quality ones (think "con" - rubycon, nichicon, nippon chemi-con, and panasonic (OK, not a "con", but still), back when we called caps "condensers"). And make sure the "low ESR" ones are replaced with low ESR ones. There aren't many other ones elsewhere - but since the power supply is the literal lifeblood of the machine, it's not a bad place to start.

The capacitor plague is over, but it doesn't mean there aren't crappy parts around, like CapXon (aka CrapXon).

There is test equipment for ESR available at a fairly low cost that allows in-circuit testing of caps so you can seek and destroy the bad ones, but it doesn't cost a lot more to do 'em all.

Also, if your repair shop is like some I've seen which have parts that have sat around a bit, the replacements may need to be reformed (which generally means around 24 hours of use) in order to recreate the oxide layer that is the dielectric so they will regain their full capacitance. You might want to disconnect the hard drive and let your TiVo sit around for a few hours powered up - even though I said 24 hours, you only need a few to get it to the point where it should work and you can let it reform while under load.

The ones most likely to go bad are the ones on the +5 and +12 Volt outputs, because that's where most of the current drawing is happening.

A good shop should be able to figure out which ones those are even without the schematic I wish were available.

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I had one bulging one replaced, but not sure which one it is. I am pretty sure it was a medium sized one (compared to the others); it wasn't the smallest, but not the largest of the bunch either. Is this the +5 or +12 volt one? Or is it really hard to tell without looking at it?

Are the two S3 boxes the same? Sounds like maybe they are if you took the drive from one and it worked in the other. If they are the same, then you could try putting the power supply from the good one into the bad one just to verify that is the problem. You might be able to get a good supply for cheaper than paying the labor rate of the repair shop for each attempted fix.

Also, if your repair shop is like some I've seen which have parts that have sat around a bit, the replacements may need to be reformed (which generally means around 24 hours of use) in order to recreate the oxide layer that is the dielectric so they will regain their full capacitance. You might want to disconnect the hard drive and let your TiVo sit around for a few hours powered up - even though I said 24 hours, you only need a few to get it to the point where it should work and you can let it reform while under load.

But I'd bet there are other bad caps first.

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If I have a power supply that has had some of the capacitors replaced, but the yellow wire (12V) is only putting out around 6-7 volts, could this be the cause? There's also a clicking noise when I have it plugged in. Could this cause it to really only put out half of the voltage it should or is it more likely just that there are some additional capacitors that need to be replaced?

My S3 was also in the reboot loop (was fine without cards in it) so I replaced it with a XL4.

Finally got back to it and tried replacing all the caps myself (went ahead and did them all). Now it is just stuck at Powering up.

I have a disk duplicator and tried doing a block copy of my 250GB drive to a spare WD Green 2TB drive I have. No change. I also tried a couple of MFS Live CD images I found on this forum both expanding to the full 2TB as well as just using 250GB on it. No change.

My soldering skills are not the best in the world so I assumed I messed something up and ordered a replacement power supply from weaknees, but I still get stuck at Powering up regardless of the power supply and drive/image combination I try.

I'm not willing to invest the money in a pre-formatted drive (it was a whim to try to put it together to give it to my mother-in-law) so I've already got my RMA to ship the power supply back.

Before I do that does anyone have any further ideas or know of a known good image for a 250B unit?

If I have a power supply that has had some of the capacitors replaced, but the yellow wire (12V) is only putting out around 6-7 volts, could this be the cause? There's also a clicking noise when I have it plugged in. Could this cause it to really only put out half of the voltage it should or is it more likely just that there are some additional capacitors that need to be replaced?

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If you have a good volt meter, try checking the AC RMS voltage on the 12 volts. If it has AC RMS volts, it is very very likely to have a bad capacitors.

I am guessing the AC RMS voltage on the 12 volts DC should be less than 0.1 volts.

If there is NOT AC voltage, I would guess that the problem is NOT bad caps.

NOTE: I have no experience on repairing TiVo power supplies; but, I do have some past experience doing Analog Power supply repair. Anyone know if TiVo Power supply is Analog or a Switching Power supply?

If I have a power supply that has had some of the capacitors replaced, but the yellow wire (12V) is only putting out around 6-7 volts, could this be the cause? There's also a clicking noise when I have it plugged in. Could this cause it to really only put out half of the voltage it should or is it more likely just that there are some additional capacitors that need to be replaced?

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That clicking noise could be the hard drive trying to start up and failing because 7 Volts can't push as much current to it as 12 V would, or it could be that the drive is trying to draw a lot more current than it's supposed to and that's what's dragging down the 12 V line, and maybe even causing the supply to shut down and then try to start again, only to find the same overload condition, and shut down again, lather, rinse, repeat.

Measure that yellow line again with the cable removed from the back of the hard drive and see if there's much difference.

If you have a good volt meter, try checking the AC RMS voltage on the 12 volts. If it has AC RMS volts, it is very very likely to have a bad capacitors.

I am guessing the AC RMS voltage on the 12 volts DC should be less than 0.1 volts.

If there is NOT AC voltage, I would guess that the problem is NOT bad caps.

NOTE: I have no experience on repairing TiVo power supplies; but, I do have some past experience doing Analog Power supply repair. Anyone know if TiVo Power supply is Analog or a Switching Power supply?

Tim S.

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TiVo supplies are very much switch mode--AC comes in, gets rectified, and then chopped at a lot higher than 60Hz to feed a much lighter transformer than would be needed for a standard rectify after step down type supply.

Which means they need low ESR 105 degree caps on the DC outs to filter all that high frequency ripple, and that's where "capacitor plague" has been biting everyone in the posterior these past several years on S2s and S3s.

Bear in mind, you'll need a meter with good enough AC frequency response because that won't be 60 or 120 Hz ripple on the output rails, it'll be somewhere in the kHzs.

My S3 was also in the reboot loop (was fine without cards in it) so I replaced it with a XL4.

Finally got back to it and tried replacing all the caps myself (went ahead and did them all). Now it is just stuck at Powering up.

I have a disk duplicator and tried doing a block copy of my 250GB drive to a spare WD Green 2TB drive I have. No change. I also tried a couple of MFS Live CD images I found on this forum both expanding to the full 2TB as well as just using 250GB on it. No change.

My soldering skills are not the best in the world so I assumed I messed something up and ordered a replacement power supply from weaknees, but I still get stuck at Powering up regardless of the power supply and drive/image combination I try.

I'm not willing to invest the money in a pre-formatted drive (it was a whim to try to put it together to give it to my mother-in-law) so I've already got my RMA to ship the power supply back.

Before I do that does anyone have any further ideas or know of a known good image for a 250B unit?

Yeah that is one of the threads I grabbed an image from. I don't know if I had found the latest one you posted on the 12th, but I just tried that one and it didn't work either. Still stuck at Powering Up.

Make sure you've run wdidle3.exe /R on that Caviar Green to see if you need to disable Intellipark.

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Is that critical for it to work at all? Unfortunately I do not have a Windows host (or a desktop) and I can't get my VM software to let the Windows VM see the bare drive in the USB enclosure.

My (limited) understanding was that it impacts how well it perform, but shouldn't stop it from working. My intent was not to use this drive for more than testing that the system is working again. If I can get the system to work and it requires a new disk, I'd pick up a new bare drive that is more suited to the task than my green.

Yeah that is one of the threads I grabbed an image from. I don't know if I had found the latest one you posted on the 12th, but I just tried that one and it didn't work either. Still stuck at Powering Up.

Is that critical for it to work at all? Unfortunately I do not have a Windows host (or a desktop) and I can't get my VM software to let the Windows VM see the bare drive in the USB enclosure.

My (limited) understanding was that it impacts how well it perform, but shouldn't stop it from working. My intent was not to use this drive for more than testing that the system is working again. If I can get the system to work and it requires a new disk, I'd pick up a new bare drive that is more suited to the task than my green.

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Intellipark interferes with warm reboots, mostly, although some people have reported that disabling it makes the difference in the TiVo booting at all in their particular instance.

What is the model number of that WD Green?

Are you running Windows on a virtual PC running on a Mac and are you running WinMFS inside that instance of Windows and can it see a drive connected via USB?

(if not, I don't understand how you're trying any of those 648 images in the first place)

If you want to buy a drive specifically for that S3, get a WD20EURS.

It's 2TB, made to do A/V work 24/7, and doesn't need Intellipark turned off, at least not the ones being sold now.

newegg or Amazon should be able to fix you up with one for $100 or less.

as an image to a cd and get an Intel bootable cd that'll let you run wdidle3.exe, but I don't think it can do it over USB.

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Nope. No joy. Doesn't see the disk.

Is there any way to connect that EADS in place of the MacBookPro's hard drive (which I assume is a SATA), not the power part but the data part?

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Nope. Barring the impracticalities of trying to run a MBP partially disassembled, all my options are older laptops with the wrong connector.

Do you know anybody that owns a PC and wouldn't have a cow at the thought of taking the cover off?

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As I think about it, I honestly can't say that I do. Everyone's moved to laptops of various types. I only have the spare green drive for my NAS (it's the RAID spare), otherwise everything I have is 2.5" drives